In the semiconductor manufacturing apparatus where the heat treatment occurs for a semiconductor substrate under the vacuum condition or atmospheric condition within the treatment chamber, the heat treatment may occur for the semiconductor substrate as it is placed on the substrate supporting/transferring tray having a substrate supporting part on its upper side, in order to ensure that the semiconductor substrate can be heated uniformly during the heating process or can be transferred to any subsequent process after the heat treatment is completed.
As shown in FIG. 7 (a), for example, a semiconductor substrate 1 may be placed on a substrate supporting/transferring tray 18 having a substrate supporting portion on its upper side, and the heat treatment may occur for the substrate 1 under the vacuum condition or atmospheric condition by placing the substrate supporting/transferring tray having the substrate placed thereon onto a substrate supporting member 2 that incorporates a heating means 4 therein for heating the semiconductor substrate.
In the embodiment shown in FIG. 7 (a), the substrate supporting/transferring tray 18 is only intended to heat the substrate 1 uniformly. Thus, when one substrate 1 for which the heating process is completed is removed from the treatment chamber (not shown) and another substrate 1 is then transferred into the treatment chamber in which it is subjected to the heating process, it is impossible to use the transfer robot or the like because there is no area on the substrate supporting/transferring tray 18 that can be supported by the transfer robot. The problem is, therefore, that when the heating process is completed for the substrate 1, the substrate 1 cannot be transferred until its temperature is lowered.
In the embodiment shown in FIG. 7 (b), the substrate supporting/transferring tray 18a has the form of a flat plate having a substrate supporting portion on its upper side, and has its outer peripheral edge 18d diametrically larger than the outer peripheral edge 2a of a substrate supporting member 2 incorporating a heating means for heating the substrate. This is disclosed in Japanese patent application as published under H2002-2695.
For the substrate supporting/transferring tray 18a shown in FIG. 7 (b), the transfer robot or the like can be used because the outer peripheral edge 18d is diametrically larger than the outer peripheral edge 2a of the substrate supporting member 2 that incorporates the heating means 4 for heating the substrate, wherein the transfer robot or the like can be operated for causing a pair of forks bifurcated at the forward end thereof to support the underside (bottom side in FIG. 7 (b)) of the outer peripheral edge 18c of the substrate supporting/transferring tray 18a. 
When the heating process is completed for the substrate 1, the substrate supporting/transferring tray 18a can be removed from the upper side of the substrate supporting member 2 of the substrate supporting/transferring tray 18a by operating the transfer robot to cause the forward ends of its pair of forks to support the underside (bottom side in FIG. 7 (b)) of the outer peripheral edge 18c of the substrate supporting/transferring tray 18a. This can be accomplished without having to wait for the temperature of the substrate 1 to be lowered. Then, another substrate supporting/transferring tray 18a that follows the preceding substrate supporting/transferring tray and having a new substrate 1 placed on its substrate supporting portion 2 may be transferred onto the substrate supporting member 2 within the treatment chamber where the heating process may occur for the new substrate 1, in the same manner as described above. This permits the heating process to occur efficiently for more than one substrate in sequence.
In the embodiment shown in FIG. 7 (b) in which the substrate supporting/transferring tray 18a in the form of the flat plate having its outer peripheral edge 18d diametrically larger than the outer peripheral edge 2a of the substrate supporting member 2 is placed on the substrate supporting member 2 incorporating the heating means 4 for heating the substrate 1 and the heating process occurs for the substrate 1 being placed on the substrate supporting/transferring tray 18a, however, it may be appreciated that heat is radiated from the outer peripheral edge side 18c of the substrate supporting/transferring tray 18a projecting beyond the outer peripheral edge 2a of the substrate supporting member 2. Thus, the temperature difference or non-uniform temperature distribution may occur between the center portion side and outer peripheral edge side 18c of the substrate supporting/transferring tray 18a, causing the substrate 1 to be heated non-uniformly during the heating process.